The present invention relates to a facsimile module self-diagnostic system which is suitable for digital circuit multiplication equipment (hereinafter often referred to as DCME) and can self-diagnose the demodulation circuit and the re-modulation circuit configuring a facsimile module built in the DCME.
The conventional self-diagnostic test for DCME is particularly performed to ensure the operation of the transmission-side adaptive differential pulse code modulation (hereinafter often referred to as ADPCM) encoding circuit and the reception-side ADPCM demodulation circuit, used for a compressed transmission process of voice signals and data signals.
Regarding such self-diagnostic testing, the section 10.1 xe2x80x9cChannel check procedurexe2x80x9d of ITU-T Recommendation G.763 xe2x80x9cDIGITAL CIRCUIT MULTIPLICATION EQUIPMENT USING 32 KBIT/S ADPCM AND DIGITAL SPEECH INTERPORATIONxe2x80x9d specifies the method of ensuring the operation of a transmission-side adaptive differential pulse code modulation encoding circuit and a reception-side ADPCM demodulation circuit, used for a compressed transmission process of voice signals and data signals.
FIGS. 6 and 7 illustrate the procedure disclosed in the above-mentioned prior art document. FIG. 6 shows the configuration of the transmission-side self-diagnostic system in DCME. In the transmission circuit, a signal discrimination circuit 31 discriminates whether an input signal from the TRUNK input terminal is a data signal or a facsimile signal (hereinafter referred to a FAX signal). In response to the discriminated voice/data discrimination signal, a voice/data signal assignment control circuit 34 controls a delay circuit 32, a test tone signal generation circuit 35, a voice/data signal ADPCM encoding circuit 36, a voice/data signal connection circuit 37, and a voice/data assignment signal generation circuit 38 in an assignment mode. The delay circuit 32 delays an input signal by a period of time for discrimination and then outputs the delayed voice/data signal to the voice/data signal ADPCM encoding circuit 36. The test tone signal generation circuit 35 generates a test tone signal at regular intervals and outputs it to the voice/data signal ADPCM encoding circuit 36.
In the voice/data signal ADPCM encoding circuit 36, a corresponding ADPCM encoding circuit is assigned according to ADPCM code control information from the voice/data signal assignment control circuit 34. The corresponding ADPCM encoding circuit subjects a voice signal, a data signal or a test tone signal to an ADPCM encoding process and then outputs the encoded signal to the voice/data signal connection circuit 37. The voice/data signal connection circuit 37 rearranges ADPCM encoded voice/data signal for multiplication and outputs the rearranged signal as a voice/data transmission signal to the multiplex circuit 43. The voice/data assignment signal generation circuit 29 generates an assignment signal for informing the opposite side of voice/data assignment information and outputs it as the voice/data assignment signal to the multiplex circuit 43.
In response to a discriminated FAX discrimination signal, the FAX signal assignment control circuit 39 controls the delay circuit 33, the FAX signal demodulation circuit 40, the FAX signal connection circuit 41, and the FAX assignment signal generation circuit 42 in assignment mode. The delay circuit 33 delays an input signal by a period of time for discrimination and then outputs the delayed FAX signal to the FAX signal demodulation circuit 40. In the corresponding FAX signal demodulation circuit 40, a corresponding demodulation circuit is assigned according to demodulation control information from the FAX signal assignment control circuit 39. The corresponding modulation circuit demodulates the FAX signal or the test FAX signal and then outputs the demodulated signal to the FAX signal connection circuit 41. The FAX signal connection circuit 41 rearranges the demodulated FAX signal for demodulation and then outputs the rearranged signal as a FAX transmission signal to the multiplex circuit 43. The FAX assignment signal generation circuit 42 generates as a FAX assignment signal an assignment signal for informing the opposite side of FAX assignment information, to the multiplex circuit 43. The multiplex circuit 43 multiplexes a voice/data transmission signal, a voice/data assignment signal, a FAX transmission signal, and a FAX assignment signal and then outputs the multiplex signal as a BEARER signal to the opposite side.
FIG. 7 illustrates the configuration of a reception-side self-diagnostic system in the digital circuit. multiplication equipment. In the reception-side self-diagnostic system, the separation circuit 44 separates a voice/data transmission signal, a voice/data assignment signal, a FAX transmission signal and a FAX assignment signal from the input multiplex signal being a BEARER signal. The voice/data assignment signal reception circuit 46 analyses a separated voice/data assignment signal and then outputs a voice/data assignment analysis signal to the voice/data signal assignment control circuit 47.
The voice/data signal assignment control circuit 47 distributively controls the voice/data signal connection circuit 45, the voice/data signal ADPCM demodulation circuit 48 and the test tone signal judgment circuit 49. The voice/data signal connection circuit 4 rearranges separated voice/data signals for an ADPCM demodulation process and then outputs the rearranged signal to the voice/data signal ADPCM demodulation circuit 48. The voice/data signal ADPCM demodulation circuit 48 subjects a corresponding signal to the ADPCM demodulation process based on the ADPCM demodulation control information from the voice/data signal distribution control circuit 47. Then, the voice/data signal ADPCM demodulation circuit 48 outputs a demodulated voice signal and a demodulated data signal to the signal connection circuit 54 and outputs a demodulated test tone signal to the test tone signal Judgment circuit 49. The test tone signal demodulation judgment circuit 49 judges whether the ADPCM-demodulated test tone signal satisfies the recommendation and then outputs the judgement result.
The FAX assignment signal reception circuit 51 analyzes the separated FAX assignment signal and then outputs a FAX assignment analysis signal to the FAX signal separation control circuit 52. The FAX signal separation control circuit 52 distributively controls the FAX signal distribution control circuit 50 and the FAX signal re-modulation circuit 53. The FAX signal distribution control circuit 50 rearranges the separated FAX transmission signals for re-modulation by the re-modulator and then outputs the rearranged signal to the FAX signal re-modulation control circuit 52. The FAX signal re-modulation circuit 53 re-modulated a Corresponding signal based on the re-modulation control information from the FAX signal re-modulation circuit 52 and outputs the re-modulates the FAX signal to the signal connection circuit 54. The signal connection circuit 54 respectively connects a demodulated voice signal, a demodulated data signal, and a re-modulated FAX signal to respective TRUNK signal output terminals and outputs them as the TRUNK output signals.
As described above, the conventional self-diagnostic system does not have the configuration of ensuring the operation of the transmission-side demodulation circuit and the operation of the reception-side re-modulation circuit in the facsimile module used for a FAX signal compressed transmission process. Hence, the problem is that the self-diagnostic system cannot recognize a failure occurring in the transmission-side demodulation circuit and the reception-side re-modulation circuit in the facsimile module.
The present invention is made to solve the above-mentioned problems.
The objective of the invention is to provide a facsimile module self-diagnostic system that can ensure the operation of the transmission-side demodulation circuit and the reception-side re-modulation circuit in a facsimile module used for a compressed FAX-signal transmission process, thus detecting a failure occurring in those circuits. Moreover, another objective of the present invention is to provide a facsimile module self-diagnostic system suitable for DCME.
The objective of the present invention is achieved by facsimile module self-diagnostic system for digital circuit multiplication equipment (DCME), comprising a signal discrimination circuit provided on a transmission side, for discriminating whether an input signal is a voice/data signal or a facsimile signal; a de lay circuit for delaying said input signal by a period of time needed for discrimination; a test facsimile signal generation circuit for generating a test facsimile signal; a facsimile signal demodulation circuit for demodulating either a delayed facsimile signal output from the delay circuit or the test facsimile signal; a facsimile signal connection circuit for rearranging a facsimile signal demodulated by the facsimile signal demodulation circuit and then outputting the rearranged signal as a facsimile transmission signal or a test facsimile transmission signal; a facsimile assignment signal generation circuit for outputting a facsimile assignment signal, the facsimile assignment signal informing a reception side of assignment information on either a facsimile signal or a test facsimile signal; a facsimile signal assignment control circuit for controlling in assignment mode the delay circuit, the test facsimile signal generation circuit, the facsimile signal demodulation circuit, the facsimile signal connection circuit and the facsimile assignment signal generation circuit; a multiplex circuit for multiplexing either the facsimile transmission signal and the facsimile assignment signal or the test facsimile transmission signal and the test facsimile assignment signal, with a voice/data transmission signal and a voice/data assignment signal obtained based on the input signal; a separation circuit provided on a reception side, for separating either the facsimile transmission signal and the facsimile assignment signal or the test facsimile transmission signal and the facsimile assignment signal from a multiplex signal transmitted from the transmission side; a facsimile assignment signal reception circuit for receiving and analyzing the facsimile assignment signal or the test facsimile assignment signal; a facsimile signal connection circuit for rearranging the facsimile transmission signal or the test facsimile transmission signal and then outputting a facsimile demodulated signal; a facsimile re-modulation circuit for re-modulating the facsimile demodulated signal output from the facsimile signal connection circuit and then outputting a facsimile re-modulated signal or a test facsimile re-modulated signal; a test facsimile signal judgment circuit for receiving the test facsimile re-modulated signal from the facsimile signal re-modulation circuit and judging whether the test facsimile re-modulated signal is at a specified value; and a facsimile signal distribution control circuit for distributing control information to the facsimile signal connection circuit, the facsimile signal re-modulation circuit and the test facsimile signal judgment circuit.
In the facsimile module self-diagnostic system according to the present invention, the test facsimile signal, which is output from the test facsimile signal generation circuit, is a signal having a DCS signal zone, a silence zone and a TCF signal zone.
In the facsimile module self-diagnostic system according to the present invention, the test facsimile re-modulated signal includes a DCS signal and a TCF signal. The test facsimile signal judgment circuit inspects the test DCS signal in a DCS signal judgement zone subsequent to a predetermined waiting zone at a first stage and inspects the test TCF signal in a TCF signal judgement zone subsequent to a predetermined waiting zone at a second stage.
In the facsimile module self-diagnostic system according to the present invention, the facsimile distribution control circuit controls the operation of the facsimile re-modulation circuit based on a test facsimile signal judgement output from the test facsimile signal judgement circuit.
According to the present invention, a facsimile module self-diagnostic system on the transmission side for digital circuit multiplication equipment (DCME), comprises a delay circuit for delaying a voice/data signal or a facsimile signal by a period of time needed for discrimination; a test facsimile signal generation circuit for generating a test facsimile signal; a facsimile signal demodulation circuit for demodulating either a delayed facsimile signal output from the delay circuit or the test facsimile signal and then outputting a modulated facsimile signal to a facsimile signal connection circuit; and a facsimile signal assignment control circuit for controlling the delay circuit, the test facsimile signal generation circuit, and the facsimile signal demodulation circuit in assignment mode.
Moreover, according to the present invention, a facsimile module self-diagnostic system on the reception side for digital circuit multiplication equipment (DCME), comprises a facsimile re-modulation circuit for re-modulating a facsimile demodulated signal output then outputting a facsimile re-modulated signal or a test facsimile re-modulated signal; a test facsimile signal Judgment circuit for receiving the test facsimile re-modulated signal from the facsimile signal re-modulation circuit and judging whether the test facsimile re-modulated signal is at a specified value and then outputting a judgment signal; and a facsimile signal distribution control circuit for distributing control information to the facsimile signal re-modulation circuit and the test facsimile signal judgment circuit.
Furthermore, according to the present invention, a facsimile module self-diagnostic system on the reception side for digital circuit multiplication equipment (DCME), comprises a facsimile re-modulation circuit for re-modulating a facsimile demodulated signal output then outputting a facsimile re-modulated signal or a test facsimile re-modulated signal; a test facsimile signal judgment circuit for receiving said test facsimile re-modulated signal from the facsimile signal re-modulation circuit and judging whether the test facsimile re-modulated signal is at a specified value and then outputting a test facsimile signal judgment signal; and a facsimile signal distribution control circuit for distributing control information to the facsimile signal re-modulation circuit and the test facsimile signal judgment circuit; wherein the facsimile distribution control circuit controls the operation of the facsimile re-modulation circuit based on the test facsimile signal judgement output from the test facsimile signal judgement circuit.